documentation

Pull request #2547: Feature/DEV-2543 7.0 D v2

Merge in WEB/documentation from feature/DEV-2543-7.0-D-v2 to release/7.0

* commit '6c2d053c7d9cf39910fd2a29f8ad0dc34897c953':
  DEV-2543 updated a comment.
  DEV-2543 updated comments.
  DEV-2543 changed privacy protocol.
  DEV-2543 added info on installing custom MIBs.
  DEV-2543 updated screenshot, addes OID names translation section, fixed command example.
  DEV-2543 command example generalization.
  DEV-2543 added screenshot, command examples generalization.
  DEV-2543 guide improvements.
  DEV-2543 added info for SNMPv3 and troubleshooting section.